Method and apparatus for decontaminating hydraulic fluids



G. J- TOPOL Nov. 26, 1963 METHOD AND APPARATUS FOR DECONTAMINATING HYDRAULIC FLUIDS Filed June 26, 1959 BY GEORGE .1. TOPOL m 2 m R I. m QK... m M iiww p. w m a I; w w m a a; *rskzf M amww M m 8 ll w 6 6. 0 H if;a 3;i2 6 2% 9 w w E w a M 3 3,1 12,195 Patented Nov. 26, 196? ice 3,112,190 METHOD AND APPARATUS FOR DECQN- TAMKNATHNG HYDRAULEC FLUID George J. Topol, Hamilton, flutario, Canada, assignor iodllowser, Inc, Fort Wayne, Ind, a corporation of 11 lane Filed June 26, 195i, Ser. No. 823,216 11 Claims. (Cl. 55-46) This invention relates to both the system and process for decontaminating hydraulic fluids and the like wherein the fluid is rendered free from solid contaminants suspended in the oil and air, gases, condensable contaminants which are either dissolved or suspended in the hydraulic fiuid.

In the usual vacuum pump system, a hydraulic fluid medium is normally employed to wet the pump components to form a seal which separates the suction and discharge compartments of the pump during its compression stroke. lf the fluid should contain contaminants such as dissolved gases or other impurities which are freed under subatmospheric pressure then such liberated gaseous materials originating from the hydraulic fluid will impair the cfficiency of the pump since the impurities themselves add to the other gases which need be evacuated.

The hydraulic fluid during pumping operation is brought repeatedly into intimate contact with the air or other material which is pumped and thereby tends to absorb air, gases, moisture and condensable vapors. For best pumping operation results, therefore, it is essential that the hydraulic fluid have continuously removed from it any such impurities which are freed when exposed to the vacuum conditions produced by the pump action so that the useful displacement of the pump is not impaired.

Otherwise, the pump would have to handle these gaseous impurities in addition to the air or other medium being evacuated. Also, it is necessary that the hydraulic fluid be itself of extremely low vapor pressure so as not to contribute gaseous ingredients which reduce the attainment of higher vacuum. if the volume of gases and vapors liberated by the oil should equal the pump displacement then the pump blanks ofl or expends its entire capacity on evacuating these impurities. Under these conditions, the pump can produce no higher vacuum.

Many proposals have been advanced for removing contaminants from the hydraulic fluid and among such proposals are those involving heating of the oil; settling, centrifuging and filtration; and so-called gas ballast. Each of these have objectionable shortcomings since they either fail to remove air or other gases which are dissolved in the oil, or else they drastically reduce pump capacity by increasing the air or other gaseous content of the oil.

In contrast with the previously used methods or" purification, it is one of the objects of the present invention to provide for removal of substantially the entire containinant content or" the oil, liquid, gaseous and solid contaminants, even though certain of the gaseous contaminants are directly soluble in the hydraulic fluid and therefore dissolved therein.

It is a further object of the invention to provide decontairnnation of the hydraulic fluid by means of a continuously operating system and process wherein the hydraulic fluid is continuously cycled for purification simultaneously with operation of the pump, so that the hydraulic fluid used in the pump is substantially contamination free. By carrying out these processes concurrently there is never necessitated deactuation of the vacuum pump to achieve oil purification. As a result, the vacuum pump is made more efiicient by continuous running and is obviously made much more effective by virtue of the improved hydraulic fluid.

Another object of the invention is to achieve oil purification by duplicating the conditions which are encountered in the pump during evacuation so that all contaminants which are freed under these conditions can be removed prior to usage of the fluid.

Among the important features of the present invention are the simplicity and adaptability of the system for purifying hydraulic fluid, the novel arrangement wherein the vacuum which is used for separating the gaseous contaminants, and the method from disposing of the gaseous contaminants liberated when exposed to subatmospheric pressures.

It will he understood that the invention is adaptable for use in a wide variety of systems, as for example, internal combustion engines where it is desired to remove solids, water, and fuel for crankcase oil; refrigerator compressors wherein lubricating oils are purified of solids, water and refrigerants. Other uses will be suggested from these example illustrations such as electrical insulating oil purification and the like.

In order to avoid the necessity of venting gas separated in the separator, the separated gas and the liquid purified are pumped through the same pump back to the reservoir from which they were originally drawn while they are handled separately. A low capacity pump will be suitable for this purpose and will also allow for the build-up of liquid upstreamof the pump during liquid discharge.

Additional objects and features of the invention will become apparent from a consideration of the following description which proceeds with reference to the accompanying drawings wherein:

FIGURE 1 is a sectional view taken through the main portion of the apparatus; and,

FEGURE 2 is an enlarged isometric view of the device for removing condensed water vapors, the lower part of the device being shown broken away to illustrate how the container for receiving the water is removably attached thereto.

Refering now to the drawings, the incoming oil which is indicated schematically by the leftward arrow in FIG- URE 1 is passed in a substantially continuous flow through the strainer it and line l2 where it enters a heater 14 which serves to elevate the temperature of the oil. The oil then leaves the heater through a line 16 which is connected to a separator indicated generally by reference numeral 18. Separator 18 includes two concentric cylinders 2 9 and 22-, which form an entry chamber 24 and a surrounding chamber 26 defined by the walls of cylinders 20 and 22. The inner cylinder 2% has a cover 23 which is fastened to flange 3%? on the outer cylinder 22; the seal 32. insures hermetic sealing of the chamber 2 4 and surrounding chamber '26.

Within the hermetically sealed chamber 24- is a tubular holder 34 which is clamped against the cover 28 by means of a threaded fastener 36 which is screwed into the threaded opening 38 at the end 41 of the holder. The fastener 36 has a shoulder 39 which is brought against the outer face of the cover 28 and a reduced diameter externally threaded neck 40 which receives a coupling 42 serving to connect the end of line 16 with passage 44 for-med in the interior of the fastener 36. A restricted orifice 46 is constructed within the fastener 36 to reduce the rate of incoming flow of oil. Between the upper end of tubular holder 34 and the inner surface of the cover 23 is a baffie 54} having an outer edge which extends beyond the circumference of cylinder 20 and is bent downwardly to divert uprising gaseous materials within chamber 24 into chamber 26. A washer 52 may be added to serve as a spacer between the baflle and cover 28. At the depending end 56 of the tubular holder 34 is a threaded opening 58 which receives bolt 60 serving to suspend a filtering element 62 through washers 64. The passage 44 in fastener 36 terminates in radial passages 66 which direct the incoming oil to within the filtering element 62.

At the base 68 of the cylinder is an outlet port 70 which is controlled by a float poppet valve referred to generally by reference numeral 72 and includes a spherical float 74, a float seat 76 and a float stem 78 which is screwed tightly into the float to hold the seat in place. The outlet line 80 is held by means of a nut 82 at the interior of chamber 24 and a second nut 84 is also received on the discharge line so that the spacer adapter 86 is held tightly between base 68 of cylinder 20 and base 33 of cylinder 22. The openings 90 and 92 in bases 63 and 88, respectively, are thereby sealed. A gasket 4 above nut 84 may be included to insure adequate sealing.

The discharge line 80 is connected with a pump 98 which displaces the fluid under pressure causing it to flow in the direction indicated by the arrow in the lower part of FIGURE 1 at the pump outlet line 100.

A bypass line 102 is connected at 104 with the discharge line 80 and includes bends 1&5, 106 and 108 which form a gooseneck leading back to the chamber 26 where it opens at 110. Another outlet 112 is connected through an elbow 114 with a vertical line 116 which passes through an opening 118 in a bottle head 120. A condensate bottle 122 has a flanged top 124 which fits within bottle head 126 and is held tightly against a sealing gasket 126. Spring 128 biases the head 120 downwardly to form a tight seal allowing water to pass through line 116 into the condensate bottle 122 but without permitting entry of air into the system.

In operation, a continuous flow of oil enters the system through line 12, is then heated by the heater 14 and then passes through orifice 46 and into the passages 44, 66, thence through the filtering element 62 where solid contaminants are removed. The incoming oil is caused to flow as described by virtue of the vacuum within the chambers 24 and 26 as produced by the pump 98.

As the oil passes through filtering element 62, it is diffused somewhat so that gaseous contaminants can more readily separate from the hydraulic fluid under the subatmospheric pressures prevailing within chambers 24 and 26. The separating gaseous contaminants flow upwardly in chamber 24 and are diverted into chamber 26. The wall of cylinder 22 being cool causes water vapor to condense on the inner surface of the wall and flow downwardly. The water collects at the base 88 and flows through line 116 and into the container 122. The decontaminated oil collects at the base 68 of the cylinder container 20 and when suflicient oil accumulates, the oil attains a level so that buoyancy of float 74 unseats the float seat 76 allowing the oil to pass through the outlet port 70 and discharge line 80 to the pump 98. The bypass line 102 becomes partially filled with oil at this stage and prevents communication of pumping action from pump 98 to chambers 24 and 26. The discharge of oil continues until the level of oil within chamber 24 lowers sufliciently to reseat the valve seat 76 closing the outlet port 70, whereupon pump 98 draws out whatever oil is contained in line 102 and establishes communication with chambers 24- and 26, exhausting the gaseous contaminants therein and producing subatmospheric pressure within chambers 24 and 26. The pump 98 at this interval is acting as a vacuum pump since it has been wetted by oil during the discharge cycle. The vacuum producing action of the pump 98 continues for a few seconds duration until the wetting action of the oil is dissipated. During this period, the incoming hydraulic fluid in chamber 24 continues to build up in level and after attaining suflicient height will operate the float valve 72 again allowing oil to flow through discharge line 80. Once the float has seated, however, a portion of its buoyancy is lost corresponding to the seat area thus causing the float valve to stay seated until the gas exhausting stage is completed.

These alternating conditions are cyclic and continuous and the decontaminated oil is returned by the pump 98 to the reservoir from which it was originally drawn, the gaseous contaminants appearing periodically as a long bubble in the discharge line. The gases thus separated are returned to the reservoir together with the oil where they are readily separated, and passed to the atmosphere. The reservoir is, of course, open to atmosphere.

The discharge float valve 72 seats and unseats by a poppet action quite rapidly so that the response is a sudden one. This is because the float buoyancy which corresponds to the seat area is restored or lost suddenly at a certain level of oil. This loss of buoyancy from the seat area also permits the float to stay in a closed position while the pump removes oil from the bypass line 162.

The pumping and evacuating cycles repeat in relatively short intervals and during the cycle operation, there is a minimum mixing of oil and gas in the discharge line, there being distinct intervals of oil pumping and vacuum action by the pump 98.

From a consideration of the operation of the system, it will be seen that the contaminants removed include solids, gases, moisture and volatile contaminants and that the single pump W produces both vacuum and pumping of the oil effecting separation of the contaminants and further serves as a means for inducing incoming flow of oil and discharge of oil for return to the reservoir. Since the water is condensed and separately removed, the pump capacity need not be large.

It may be desirable in some applications to further cool the wall of cylinder 22 to make more effective the water condensation. This is well within the teaching of the present invention. Also, since the whole system is closed and communicates with the atmosphere only through the oil reservoir, it is impossible to lose any oil should the pump 98 fail or in the event of oil foaming.

The poppet action of float valve 72 may be replaced by a siphon arrangement if desired with equivalent results. To achieve this, the discharge line is simply passed upwardly within chamber 24 and then bent downwardly so that its open end terminates at whatever minimum level of oil is desired within chamber 24. Thus, for oil levels above such outlet opening, oil will be forced through the outlet line, and at levels below the opening the pump 98 will produce vacuum through bypass line 102.

Periodically the container 122 is removed and emptied of water content, but, if desired, an automatic condensate drain may be provided.

While only certain selected embodiments of the invention have been chosen to illustrate the invention, it will be understood that these are only illustrative of the inven' tion. It is intended that such revisions and variations of the invention as are reasonably to be expected on the part of those skilled in the art, and which incorporate the herein disclosed principles will be included within the scope of the following claims.

I claim:

1. An oil conditioner for removing contaminants comprising a receiving chamber having an inlet for admitting a flow of oil therein, a filtering element arranged in series with the incoming flow of oil to remove contaminants from said incoming oil flow as the oil enters said receiving chamber, means surrounding said inlet chamber and defining a hermetically sealed closed volume chamber, said closed volume chamber being proportioned to provide a spacing surrounding said receiving chamber, an outlet at the base of said receiving chamber for discharging oil rendered contamination-free within said receiving chamber, a control valve for said outlet including an operatively connected float located in said receiving chamber and responsive to the level of oil therein for opening and closing said outlet at predetermined levels, a discharge line connecting with said outlet, a pump in said discharge line for removing oil from said receiving chamber when said control valve is operated to open said outlet, and a bypass line connecting said discharge line upstream of said pump and means surrounding said inlet chamber through a looped portion which is filled with oil when said control valve is open during oil discharge to isolate said hermetically sealed volume from said pump, said oil pump being connected with said hermetically sealed volume through said bypass line to produce a Vacuum therein when said outlet valve is closed and to exhaust gaseous contaminants released from the incoming flow of oil as it is exposed to vacuum within said receiving chamber.

2. An oil conditioning system comprising hermetically sealed means for receiving an incoming flow of oil for decontamination, filtration means for removing filterable contaminants from the flow of oil before entry thereof into said hermetically sealed means, means surrounding said hermetically sealed means and providing a spacing therefrom for receiving the contaminants liberated as gaseous materials from the oil under subatmospheric pressure within said hermetically sealed means, an outlet line for discharging decontaminated oil collected within said hermetically sealed means, an outlet means for operating an outlet valve responsive to the quantity of decontaminated fluid within said hermetically sealed means, a container for collecting water vapors condensed within said spacing as a portion of said gaseous contaminants, a pump in said outlet line for Withdrawing the decontaminated fluid through said outlet line, and a bypass line interconnecting said outlet line upstream of said pump and spacing which receives suiflcient oil therein while said outlet valve is open to sever communication between said pump and spacing, said outlet line forming an interconnection between said spacing and pump when said valve is closed to develop subatmospheric pressure within said hermetically sealed means to separate the gaseous contaminants in the oil and thereafter exhaust said gases.

3. An oil conditioning system comprising hermetically sealed means for receiving an incoming flow of oil for decontamination, filtration means for removing filterable contaminants from the flow of oil before entry thereof into said hermetically sealed means, means surrounding said hermetically sealed means and providing a spacing therefrom for receiving the contaminants liberated as gaseous materials from the oil under subatmospheric pres sure within said hermetically sealed means, an outlet line for discharging decontaminated oil collected within said hermetically sealed means, an outlet means for operating an outlet valve responsive to the quantity of decontaminated fluid Within said hermetically sealed means, a container for collecting water vapors condensed within said spacing as a portion of said gaseous contaminants, a pump in said outlet line for withdrawing the decontaminated fluid through said outlet line, and a bypass line interconnecting said outlet line upstream of said pump and spacing which receives suflicient oil therein While said outlet valve is open to sever communication between said pump and spacing, said outlet line forming an interconnection between said spacing and pump when said valve is closed to develop subatmospheric pressure within said hermetically sealed means to separate the gaseous contaminants in the oil and thereafter exhaust said gases, means for condensing the water vapor portion of said gaseous contaminants, and means for collecting said condensed water for removal.

4. A conditioner for decontaminating hydraulic fluids comprising a hermetically sealed chamber, means for continuously passing a flow of said hydraulic fluid into said sealed chamber, filtration means for removing solid contaminants from said flow of hydraulic fluid, a jacket surrounding said hermetically sealed chamber and providing a spacing which separates said jacket and chamber and receives gaseous contaminants freed from the hydraulic fluid in said chamber under subatmospheric pressure, a discharge line connecting with said chamber to remove the decontaminated hydraulic fluid therein, a pump in said discharge line to displace said hydraulic fluid under pressure in said discharge line, valve means for controlling the flow of decontaminated fluid from said chamber through said discharge line, and a bypass line connecting said discharge line upstream of said pump and spacing to communicate the pumping action of said pump to said spacing and thereby produce a vacuum within said chamber serving to withdraw gaseous contaminants in said spacing :When said valve means is closed terminating fluid flow in said discharge line, said bypass line being at least partially filled to sever communication between said pump and spacing when said valve means is open, and means for continuously cycling the decontaminated hydraulic fluid from said chamber under the displacement pressure of said pump.

5. A system for decontaminating hydraulic fluid comprising a sealed chamber for receiving a continuous flow of said hydraulic fluid therein, a discharge line connecting with said sealed chamber to withdraw decontaminated hydraulic fluid therein, a pump in said discharge line to displace the hydraulic fluid therein under pressure, means for intermittently interrupting the flow of fluid from said chamber through said discharge line, and a bypass line connecting said discharge line upstrearn of said pump and said sealed chamber and being sufficiently filled with hydraulic fluid during hydraulic fluid flow to interrupt communication or" said pump therethrough to said chamber, said bypass line being cleared of hydraulic fluid by said pump when fluid flow is interrupted within the discharge line by said pump to develop VZtOlllllIl'l in said chamber and exhaust gaseous contaminants therein liberated from said hydraulic fluid under the sub-atmospheric pressure within the chamber.

6. The system in accordance with claim 5 including means for separating the gaseous contaminants from the chamber containing said hydraulic fluid and thereafter condensing the water vapor portion of said gaseous contaminants for collection.

7. The system in accordance with claim 5 including means for preliminarily treating the flow of oil before entry into said chamber and including a filter for removing solid contaminants and a heating element for elevating the temperature thereof, said filter serving to diffiuse the flow of oil as it enters said chamber whereby the gaseous contaminants are more readily separated under subatmospheric pressure.

8. Fire system in accordance with claim 5, including means for recycling said decontaminated hydraulic fluid.

9. A conditioner for decontaminating hydraulic fluids comprising a hermetically sealed chamber, means for continuously passing a flow of said hydraulic fluid into said sealed chamber, a jacket surrounding said hermetically sealed chamber and providing a spacing which separates said jacket and chamber and receives gaseous contaminants freed from the hydraulic fluid in said chamber under subatmospheric pressure, a discharge line connecting with said chamber to remove the decontaminated hydraulic fluid therein, a pump in said discharge line to displace said hydraulic fiuid under pressure in said discharge line, valve means for controlling the flow of decontaminated fluid from said chamber through said discharge line, and a bypass line connecting said discharge line upstream of said pump and said spacing to communicate the pumping action of said pump to said spacing and producing thereby a vacuum within said chamber serving to Withdraw gaseous contaminants in said spacing when said valve means is closed terminating fluid flow in said discharge line, said bypass line being at least partially filled to sever communication between said pump and spacing when said valve means is open, and means for continuously cycling the decontaminated hydraulic fluid from said chamber under the displacement pressure of said pump.

10. A conditioner for decontaminating hydraulic fluids comprising a hermetically sealed chamber, means for continuously passing a flow of said hydraulic fluid into said sealed chamber, a jacket surrounding said hermetically sealed chamber and providing a spacing which separates said jacket and chamber and receives gaseous contaminants freed from the hydraulic -'fiuid in smd chamber under subatrnospheric pressure, a discharge line connecting with said chamber to remove the decontaminated hydraulic fiuid therein, a pump in said discharge line to displace said hydraulic fiuid under pressure in said discharge line, valve means for controlling the flow of decontaminated fluid from said chamber through said discharge line, and a bypass line connecting said discharge line upstream of said pump and said spacing to communicate the pumping action of said pump to said spacing and producing thereby a vacuum within said chamber serving to exhaust gaseous contaminants in said spacing when said valve means is closed terminating fluid flow in said discharge line, said bypass line being at least partially filled to sever communication between said pump and spacing when said valve means is open.

11. A process for continuously decontaminating hydraulic fluids and the like comprising the steps of: passing a continuous flow of fluid within a hermetically sealed chamber, separating the gaseous contaminants freed from said fluid under subatmospheric pressure within said sealed chamber, discharging said fluid under pressure intermittently through a discharge line containing displacement pump having a connection with said chamber through a control means responsive to the quantity of fluid therein, and periodically exhausting gaseous contaminants from said chamber by said pump through a passage connecting said discharge line upstream of said pump and said chamber, said passage being sufficiently filled with fluid during discharge operation of said pump to interrupt vacuum producing action of said pump.

References Cited in the file of this patent UNITED STATES PATENTS 2,355,057 Copeland Aug. 8, 1944 2,555,452 McIntyre June 5, 1951 2,811,218 Winslow Oct. 29, 1957 

11. A PROCESS FOR CONTINUOUSLY DECONTAMINATING HYDRAULIC FLUIDS AND THE LIKE COMPRISING THE STEPS OF: PASSING A CONTINUUS FLOW OF FLUID WITHIN A HERMETICALLY SEALED CHAMBER, SEPARATING THE GASEOUS CONTAMINANTS FREED FROM SAID FLUID UNDER SUBATMOSPHERIC PRESSURE WITHIN SAID SEALED CHAMBER, DISCHARGING SAID FLUID UNDER PRESSURE INTERMITTENTLY THROUGH A DISCHARGE LINE CONTAINING DISPLACEMENT PUMP HAVING A CONNECTION WITH SAID CHAMBER THROUGH A CONTROL MEANS RESPONSIVE TO THE QUANTITY OF FLUID THEREIN, AND PERIODICALLY EXHAUSTING GASEOUS CONTAMINANTS FROM SAID CHAMBER BY SAID PUMP THROUGH A PASSAGE CONNECTING SAID DISCHARGE LINE UPSTREAM OF SAID PUMP AND SAID CHAMBER, SAID PASSAGE BEING SUFFICIENTLY 